This invention relates in general to a method and catheter for delivering a liquid into a uterus from an external source and, more particularly, for administering medication to the extra-amniotic space in an impregnated uterus during the first or second trimester whereby the fetus is aborted.
Numerous attempts have been made to provide a catheter capable of safe and easy operation for the purpose of administering liquid medications into an impregnated uterus. Examples of existing such devices are shown in the following patents herewith:
Kistler Pat. No. 868 450; Miller Pat. No. 3 459 176; Bell Pat. No. 3 509 884; and Gutnick Pat. No. 3 848 602.
Other, less relevant patents include: Knapp Pat. No. 397 060; Lamson No. Pat. 2 457 244; and Matthews et al. Pat. No. 3 253 594.
Applicant believes that the invention claimed herein is clearly distinguishable from the aforesaid prior art.
Existing devices have all failed for one reason or another to provide safe, optimum results particularly where the purpose is to abort a fetus in the second trimester. Drugs which have been particularly successful in effecting abortion include, but are not necessarily limited to, the following:
Pge.sub.2 or a salt thereof PA1 Pgf.sub.2.alpha. or a salt thereof
These drugs are discussed in U.S. Pat. No. 3 852 465 entitled: ABORTION BY MYOMETRIAL ADMINISTRATION OF PROSTAGLANDINS.
Existing catheters for delivering liquid medication into a uterus have not been formed to fit snugly and properly within the cervix and, accordingly, either the cervix has been unnaturally dilated or there has been leakage of the medication back along the catheter, thereby defeating the purpose of administering the medication.
For some time, it has been recognized that certain drugs in liquid form could improve the relaxation of the cervix even though substantial amounts thereof leaked through the cervix, provided that such leaked amounts could be contained or retained adjacent the external os.
Accordingly, a primary object of this invention is the provision of an improved catheter and method capable of delivering a liquid medication into the extra-amniotic space of an impregnated uterus so that leakage of the medication is virtually eliminated and, to the extent that some leakage occurs, it is essentially trapped adjacent the external os of the cervix where it can continue to perform its function of inducing dilation of the cervix.
A further object of this invention is the provision of a catheter, as aforesaid, having two flanges arranged for location externally of and at the opposite ends of the cervix so as to prevent accidental ejection or ascension of the catheter relative to the uterus.